1. Field of the Invention
This invention relates to a photographic paper exposing method for printing images on photographic paper drawn out of a paper storage by irradiating the paper with light based on image data, and an optical digital printer employing this photographic paper exposing method.
2. Description of the Related Art
In an optical printer of the liquid crystal shutter type or the CRT type, a photosensitive material (which generally is photographic paper and will be referred to hereinafter as such or just as paper) must be positioned accurately in close contact with a beam emitting surface in time of exposure. A printer of the line exposure type, in particular, exposes photographic paper line after line while transporting the photographic paper. In order to print images with a condition to minimize a blank in a forward end region of elongate photographic paper, it is preferable to transport the photographic paper downstream of an irradiating point in an exposure unit once, and then expose the paper while drawing the paper backward.
However, the process of feeding the photographic paper downstream of the exposure unit and drawing the paper backward again to print each image thereon cannot promptly meet a demand for continuously printing a plurality of images on the photographic paper. In former times when digital printing was rare, one index print is added to prints in each order. Today, in an age of digital printing, a photo processing agent prints digital image data obtained from digital cameras and the like on photographic paper. The processing agent is required to process promptly a sudden order for a plurality of digital prints.